【摘要】 笔者对发财树根腐尖孢镰刀病菌进行了分离纯化并对其生物学特性进行了研究。结果表明:尖孢镰刀病菌在各个温度下生长速度依次为27℃>24℃>30℃>33℃>36℃>40℃,生长率依次为:97.93%>95.48%>12.75%>4.93%>2.23%>1.48%,27℃为最适生长温度。含毒介质培养生长速率法对药剂的筛选试验表明:精甲咯菌腈在有效浓度为62.5 mg/L,稀释浓度1000倍时的抑制率最高,达80.87%,EC50为64.59 mg/L,用最小二乘法计算的药剂的毒力回归方程为:Y=4.351+0.359x;嘧菌酯在有效浓度为250 mg/L,稀释浓度1000倍时,抑制率较明显,为74.19%,EC50为78.17 mg/L,毒力回归方程为:Y=2.419+1.363x;甲基硫菌灵在有效浓度为700 mg/L,稀释浓度1000倍时,抑制率较明显,为85.80%,EC50为202.61 mg/L,毒力回归方程为:Y=0.575+1.919x。更多还原

【Abstract】 The thesis aims to study the biological characteristics of Fusarium oxysporum,which is isolated and purified from Pachira macrocarpa.The results showed that the growth rate of F.oxysporum varied under),and the respective growth rate was:97.93%95.48%>12.75%>4.93%>2.23%>1.48%,and the optimum growth temperature for F.oxysporum was 27℃.Growth velocity mensuration containing poisonous medium culture was used to screen various fungicides that could inhibit the growth of F.oxysporum.The results showed that:the fludioxonil reached the highest inhibitory rate(80.87%)attheeffectiveconcentrationof62.5 mg/Lunder1000 timesdilution,andEC50 valuewas64.59 mg/L.The chemical toxicity regression was Y=4.351+0.359 x calculated using the least square method.Azoxystrobin at the effective concentration of 250 mg/L under 1000 dilution,reached the highest inhibitory rate of 74.19%,and the EC50 value was 78.17 mg/L.The virulence regression equation was:Y=2.419+1.363 x.Thiophonatemethyl inhibited the pathogen most effectively(85.80%) at the concentration of 700 mg/L under 1000 times dilution,the EC50 value was 202.61 mg/L and toxicity regression equation was Y=0.575+1.919 x.更多还原